Home made board for multi purpose

I’ve started to design my own board. It is the first time that I shape a board so I am probalby wrong on some points

It is a rather high volume (140l). It will be made of XPS foam with external dimensions of 1800x600x160.
The electronics and batteries will be in the board, which explains the great thickness. Since I don’t want to step on the battery box, I’ll attach a plywood plate with a quick-lock mechanism to the top.
On the bottom I create a channel to improve the speed
I need to add on a surf mat to cover everything…

The board will be made of 4 layers of 40mm XPS sheet covered with 163gr/mm2 of fiberglass.
To fix the motor or the foil, I will insert a 12mm plywood plate that I will screw to two beech reinforcements (12x20x1000).

The quick locking mechanism is made of 3d printed tpu parts. To improve the locking speed, it is composed of 2 helixes, a 5 mm pitch…The assembly seems to work fine but I wonder if the tpu will adhere to the epoxy. There is an anti-rotation on the nut that is not shown in the photo.

At the beginning, it will be equipped with the propulsion (6384 vesa 12s 200a) that I designed for my paddle. If everything goes as planned, I will invest in a foil.

Did you print that complete motor fin? What motor fits in there?